In spread spectrum receiver systems, correlation pulses are periodically generated by a correlator in the receiver system. The correlation pulses are generally mixed with a background of noise. The receiver system must detect the repeated correlation pulse in order to establish lock and receive the transmitted information.
In communication systems which produce periodic correlation pulses, there is a trade-off between the probability of detecting the correlation pulse and the generation of false alarms due to the erroneous detection of correlation pulses. The allowable false alarm rate can vary substantially from one application to another and can require change from one time to another for a given system.
Therefore, there exists a need for a method and apparatus for detecting a repeated correlation pulse within a data stream in a noisy environment. The possibility of detecting the pulse and of incurring false alarms must also be adjustable to meet the requirements of different communication systems and of changing requirements for a particular system.